Green onions, also known as scallions, are onions that are harvested early in their development, before they form a large bulb. Mexican green onions are a specific variety of green onion that are allowed to mature longer than typical green onions. This means that Mexican green onions have a larger white bulb. Green onions are a member of the Allium species group, which includes all varieties of onions, shallots, and garlic. The words onion, shallot and scallion are all derived from the Greek word askolonion, which is a word derived from the town of Ashkelon, where the ancient Greeks believed that the various types of onion originated. Onions have been used throughout many parts of the world for ages. Onions are used worldwide, because they are very hardy and can be grown in a wide range of climates and soil types. They have been used for at least 5,000 years, both harvested from the wild and purposefully cultivated. In terms of flavor, Mexican green onions are similar to mature onions, although much milder. Mexican green onions have a slightly stronger flavor than less mature scallions. The white root of the plant has a crunchy texture similar to that of bulbous onions, and the green shoot has a similar crunch, but it has a more fibrous, grassy texture.
Mexican green onions can be used in any situation that calls for green onions. They are used both raw and cooked, but they are most often used raw, since cooking them can destroy their delicate texture. If they are used cooked, they are generally cooked very lightly, either grilled briefly or blanched. These cooking methods bring out the sweeter notes of the onion, while maintaining its delicate crunch. Because the Mexican green onion is more mature and robust than most varieties of green onion, they hold up to cooking a lot better than the younger, more delicate kinds. Mexican green onions are good to use in recipes that require long simmering, such as soups. Green onions are considered a staple in Chinese, Japanese and Southeast Asian cuisine. Green onions are a member of the “three G’s” of Asian cooking, alongside garlic and ginger. These three ingredients can be found in almost any Chinese, Japanese or Southeast Asian recipe, including dishes such as stir fry, fried rice, miso soup, many varieties of sushi, Kung Pao chicken, Thai curry, and so forth. Green onions are also commonly used in Mexican and Tex-Mex cooking in a variety of recipes like salsas, and as toppings for tacos, tostadas and burritos. In general, green onions are used alongside other fresh ingredients, in light, spicy dishes. They go well with grilled, light meats like salmon, chicken and lean pork. Scallions also work well in fresh spring salads alongside romaine lettuce, peas, radish and carrots. Citrus is a particularly good pairing for green onions.
To tell if a Mexican green onion is fresh, feel the white bulb at the end of the onion. It will be firm to the touch, and should be a clean white color, that slowly fades to green further up the plant. The green shoot will feel firm, yet slightly flexible and moist to the touch. If the white root portion of the scallion begins to yellow, and the green shoot is cracked and flaky, the onion is not fresh and should not be used. Green onions should be kept refrigerated and wrapped in plastic. They will last for about a week to ten days. Green onions can also be frozen, and will stay usable for up to a year. When preparing green onions, always begin by thoroughly rinsing them to remove any dirt or debris. Then, remove the white roots that protrude from the bulbous portion using a knife. The green shoot of the scallion grows increasingly fibrous farther up, so it is generally the case that the last inch or two of the onion is left unused due to its unpleasant texture.